His comment came after a frustrated Rep. Mike Doyle (D-Pa.) said that Democrats "have negotiated with terrorists" who "have made it impossible to spend any money," according to Politico's sources in the room.

Biden responded to Doyle by saying that the Tea Party Republicans "have acted like terrorists," Politico said, citing several sources in the room. Biden's office declined to comment to Politico.

Rep. George Miller and another lawmaker confirmed Biden's quote to TPM, but both stressed that Biden was simply concurring with what Doyle said.

Biden also reportedly told Democrats that President Barack Obama would have invoked the 14th Amendment to avoid defaulting, according to the Huffington Post's Jennifer Bendery.

Late update: RNC Chair, Reince Priebus, tweets: "[Vice President Biden] more than crossed a line today when he called fiscal conservatives "terrorists". I demand an apology."